Helter Skelter was for me the biggest fumble Ennis ever did (and I quite like some of his Dredds to put that into context.

It has his worst excesses of hero worshipping Dredd - "he is OK, and even if he does shoot you for littering and oppress you, he doesnt get paid or even thanked for it"

Worse than that, it turns into a "Lawmaster tour of North Mega-City" - the motivation of the villains makes no sense! "Dredd was a minor irritation in our dimension, but we hate him so much!"

If they ahd thought through the consequences of Dredd dying at the hands of Judge Cal, you could ahve had a very interesting story - Dredd isnt around, and things snowball from there - Cal and Kazan are trying to abandon their universe to Dredds due to Judge Death gaining a foothold - Dredd has to go to the alternate universe, where we see how much worse things would ahve been without Dredd (and maybe make that point Ennis is making without having to actually say it)